- Stark Industries
- War Machine (Lt. Col. James "Rhodey" Rhodes) (First appearance as War Machine)
- Howard Stark (Appears on a computer screen, TV, or hologram only) (First full appearance)
- Black Widow (Agent Natasha Romanoff / "Natalie Rushman") (First appearance historically) (Joins Stark Industries)
- Director Nick Fury (First full appearance)
- Agent Phil Coulson
- Whiplash (Ivan Vanko) (Only appearance; dies)
- Hammer Advanced Weapons Systems (First appearance)
- Christine Everhart
- Anton Vanko (Only appearance; dies)
- WHiH World News
- Chess Roberts (First appearance) (Cameo)
- Stan Lee
- Senator Stern (First appearance)
- Ten Rings
- Unnamed member (First appearance)
- Lemieux (First appearance)
- Rebecca (First appearance)
- United States Air Force
- Stark Industries
- Bambi Arbogast (First appearance)
- Oracle Corporation
- WHiH World News
- U.S. Army (Mentioned)
- U.S. Marines (Mentioned)
- U.S. Navy (Mentioned)
- New York Police Department (Mentioned)
Races and Species
- Russia (First appearance)
- Moscow (First appearance)
- White House (First appearance)
- Moscow (First appearance)
- United States of America
- New York
- Washington, D.C. (First appearance)
- Virginia (On-screen)
- Principality of Monaco (First appearance)
- Monte Carlo (First appearance)
- Russia (First appearance)
- Iron Man Armor
- Arc Reactor
- Iron Man's Briefcase
- War Machine armor (Iron Man MK II refit)
- Whiplash Harness (Only appearance) (Destroyed)
- Whiplash Armor (Only appearance) (Destroyed)
- Captain America's Shield (replica) (Cameo)
- Mjolnir (First appearance) (Cameo)
- Black Widow's Gauntlets (First appearance)
- Tony Stark's New Element (First appearance)
Six months after the end of Iron Man, Tony Stark (Robert Downey, Jr.) has used his Iron Man armor to bring about a negotiated peace treaty between the major superpowers of the world, and his immense popularity with the general public is only furthered when he fulfills his father's dream by opening the "Stark Expo", to showcase all the latest inventions that will benefit the world. Stark is, however, still vilified by the United States government, and Senator Stern (Gary Shandling) in particular, who demands that he hand his armor technology over for military application. Stark refuses, publicly shaming rival Justin Hammer (Sam Rockwell) of Hammer Industries in the process by highlighting his own failed attempts at recreating the technology. All is not well in Stark's life, however: he has discovered that the palladium in the arc reactor keeping his heart beating has begun to poison his body, slowly killing him, and all attempts to find a substitute element have failed. Slowly going off the rails as a consequence of what he believes to be his impending death, he appoints his former personal assistant Pepper Potts (Gwyneth Paltrow) CEO of Stark Industries, replacing her with Natalie Rushman (Scarlett Johansson).
While racing in Monaco, Stark is attacked by Ivan Vanko (Mickey Rourke), who has constructed a miniaturized arc reactor of his own, including whip-like attachments harnessing the electrical energy. Defeating Vanko with the aid of his Mark V armor (a transforming briefcase), Stark discovers that Vanko is the son of disgraced Russian physicist Anton Vanko, who collaborated on the first arc reactor with Stark's father Howard (John Slattery). When Stark visits Vanko in prison to tell him how inefficient his tech was, Vanko reveals her knows about his palladium poisoning. Later, a bomb hidden in a potato and a prisoner with the same number as him are placed in his cell, Vanko escapes, using the bomb to fake his own death, before bribed guards bring him to a revenge-seeking Justin Hammer. Hammer asks that he help fashion a line of "Iron Drones" that he will use to upstage Stark at his own Expo. Vanko agrees to, on the condition that Hammer brings him his parrot he left back in Russia; Hammer brings the parrot but Vanko claims that it's not his pet. However, Vanko modifies the suits to be more than just manned armor, but automated drones. Hammer gets very angry that Vanko went behind his back and had him under house arrest.
Meanwhile, Tony throws what he believes will be his last birthday party and promptly proceeds to get drunk whilst wearing the Iron Man armor, forcing his friend Lt. Colonel James Rhodes (Don Cheadle) to don the Mark II armor and subdue him. Disgraced, Stark is approached by Nick Fury of S.H.I.E.L.D. (Samuel L. Jackson), who provides him with a chest of his father's old artifacts that can hopefully be used to find a cure for his palladium poisoning. Reviewing the film reels in the chest, Stark discovers a message from his father that leads him to the original 1974 diorama of the Stark Expo: in reality, a disguised diagram for the atomic structure of a new element, something his father couldn't create with the technology of his day; Howard realized that his son would be able to do so in the future. Stark hand-builds a particle accelerator with the aid of his computer J.A.R.V.I.S. (voiced by Paul Bettany) and synthesizes this new element, creating a new triangular chest arc that cures his poisoning.
Simultaneously, at Stark Expo, Hammer unveils his new military drones, captained by Rhodes in a heavily-weaponized version of the confiscated Mark II armor. Stark arrives at the expo, and unfortunately, it is soon discovered that Vanko, who had his guards hung by the neck, has complete control of both the drones and Rhodes's new armor, taking control and going on the attack moments after Stark arrives. As Stark battles against these remote-controlled enemies, Happy Hogan (Jon Favreau) and Natalie (an undercover S.H.I.E.L.D. agent named Natasha Romanoff) race to Hammer's Queens facility to stop Vanko; en route, Natalie gets changed into a catsuit while telling Happy to keep his eyes on the road. When they arrive, Natalie tells Happy to stay in the car but he insists on helping. However, the latter was busy with one security guard while Natalie took out all the rest. Unfortunately, Vanko has already departed for the Expo in a new, more powerful suit of armor, but Natalie is able to give Rhodes control of his armor again so that he and Stark can fight Vanko together.
The two armored allies combine their powers and successfully take Vanko down, but his armor and drones are revealed to have been equipped with self-destruct charges. As they begin to go off, Stark races to save Pepper, who was standing close to one of the drones, rescuing her at the last minute. After landing on a roof she quits her CEO position, and she finally gives Tony a kiss, to which they both find Rhodes sitting a few meters away. He then claims he was there first so they should get their own roof after Stark tries to defend himself. He decides to keep his current suit before flying off.
At a debriefing, Fury informs Stark that while they want Iron Man in the "Avengers Initiative", Stark himself is considered unsuitable for the program. However, S.H.I.E.L.D. wants to hire Stark as a consultant. Stark agrees on the condition that Senator Stern present him and Col. Rhodes with their medals for bravery. But when Stern was attaching the medal to the former, he gives a slight poke at Stark for calling him a prick, before they all smile for the cameras.
In a post-credits scene, S.H.I.E.L.D. agent Coulson (Clark Gregg) is seen driving to a remote impact crater in the New Mexico desert. As he informs Fury over the phone that they have "found it", the crater is shown to contain Mjolnir, the hammer of Thor.
- Robert Downey Jr. as Iron Man / Tony Stark
- Davin Ransom as Young Tony Stark
- Gwyneth Paltrow as Pepper Potts
- Don Cheadle as War Machine / Lt. Col. James "Rhodey" Rhodes
- Scarlett Johansson as Black Widow / Natasha Romanoff
- Sam Rockwell as Justin Hammer
- Clark Gregg as Agent Phil Coulson
- John Slattery as Howard Stark
- Mickey Rourke as Ivan Vanko
- Samuel L. Jackson as Nick Fury
Paul Bettany, Director Jon Favreau, Leslie Bibb, and Tim Guinee reprise their roles as J.A.R.V.I.S., Happy Hogan, Christine Everhart, and Major Allen, respectively. Garry Shandling portrays Senator Stern. Kate Mara appears as a US Marshal. Christiane Amanpour, Larry Ellison, Elon Musk, and Bill O'Reilly appear as themselves in the film. DJ AM appears as himself, posthumously. The film is also dedicated in his memory. Eric L. Haney makes a cameo as General Meade. Yevgeni Lazarev portrays Anton Vanko. Helena Mattsson and Anya Monzikova portray Rebecca and Rebeka, respectively. Olivia Munn makes a cameo as Chess Roberts. Stan Lee makes a cameo as a Larry King look-alike. Jon Favreau's son Max makes an appearance as a Stark Expo attendee saved by Iron Man from a drone.
- A box office gross of $128,600,000 was recorded for opening weekend. It grossed $312,433,331 in the United States and Canada, as well as $311,500,000 in other markets, giving the film a worldwide total of $623,933,331.
- Samuel L. Jackson was promised that Nick Fury would be given more screen time by director Jon Favreau. Jackson almost did not return to play Fury, due to problems with contract negotiations, but secured a landmark nine-picture deal to play Nick Fury not only in this film but in many other Marvel Studios productions.
- Mickey Rourke paid a visit to Butyrka Prison, Moscow to prepare for his role as Whiplash.
- Early storyboards of the film showed that it was planned for War Machine to kill Justin Hammer when his suit was in control of Ivan Vanko.
- An alternative ending showed Vanko attacking Pepper Potts at the Stark Expo, but being killed by War Machine.
- The scene featuring Iron Man and War Machine fighting side by side against the Hammer Drones was conceived by concept artist Adi Granov and director Jon Favreau early into the film's development.
- During an interview with The Huffington Post, Peter Parker actor Tom Holland proposed the idea that his character made an uncredited appearance in Iron Man 2, as the little boy with an Iron Man mask whom Tony Stark saves from a Hammer Droid at the Stark Expo. Spider-Man: Homecoming director Jon Watts subsequently supported the possibility, additionally revealing he got the idea to attribute Peter Parker's identity to said little boy while rewatching all Marvel Cinematic Universe movies in preparation for Homecoming. While the idea gained traction online, when Holland talked with Marvel Studios President Kevin Feige, he didn't confirm it.